A common way to form images on media, such as paper, is to use a fluid-ejection device, such as an inkjet-printing device. An inkjet-printing device has a number of inkjet-printing mechanisms, such as inkjet printhead assemblies. Each inkjet printhead assembly has a printhead die having a number of inkjet nozzles that eject ink, such as differently colored ink, in such a way as to form a desired image on the media.
A printhead assembly can be prone to the formation or inclusion of gaseous bubbles, sludge, and/or contaminants therewithin. To ensure that such gaseous bubbles, sludge, and contaminants do not affect image quality during image formation, priming may be periodically performed. Priming desirably expels any gaseous bubbles and removes any sludge and contaminants.